1. Technical Field
The present invention relates to a liquid developer-preparing apparatus.
2. Related Art
As developers used for developing an electrostatic latent image formed on a latent image carrier, there are a dry toner which refers to a toner used in a dry state and constituted with materials including a colorant such as a pigment and a binder resin, and a liquid developer which is obtained by dispersing a toner in a carrier liquid having electrical insulation properties.
The dry toner is prepared by a dry pulverizing method that pulverizes materials including a colorant and a binder resin in a dry state. On the other hand, for the liquid developer, an insulating liquid is used as a medium, and toner particles in the liquid developer are pulverized in a wet state. Accordingly, a developer containing toner particles having a volume average particle size smaller than that of the above dry toner is obtained. Compared to the dry toner, the liquid developer obtained by the wet pulverizing method described above shows superior reproducibility of fine line images, gradation reproducibility, and color reproducibility and is more optimal for a high-speed image forming method.
In recent years, as resolution has been increased in forming images, yet smaller toner particles compared to the volume average particle size of toner particles in the related art have been required. However, in a method of preparing a liquid developer used in the related art, it takes a long time for pulverizing toner particles to obtain a volume average particle size required for high resolution, and large pulverizing energy is required. In addition, in the wet pulverizing method used in the related art, when the dispersibility of toner particles in a liquid developer is insufficient, sedimentation of the toner particles is caused when the developer is left as is for a long time, and the toner particles in the liquid developer aggregate in some cases.
In order to obtain a liquid developer in which small-sized toner particles suitable for high resolution are stably dispersed, several methods have been proposed.